On Aug. 5, 1974, shortly after losing a case at the Supreme Court, the administration of Richard Nixon released an Oval Office recording that it had kept secret to that point. In the tape, Nixon and his aides discussed how to cover up the administration’s involvement in the break-in at the Watergate Hotel, determining that former CIA deputy director Vernon Walters could call acting FBI director Pat Gray and tell the FBI to back off any further investigations.

The release of the tape was definitive proof that Nixon himself was involved in an effort to coverup the break-in and block investigations. The House Judiciary Committee had already voted to advance articles of impeachment against Nixon to the full House, including one focused on obstruction of justice and Nixon’s having “engaged personally and through his close subordinates and agents, in a course of conduct or plan designed to delay, impede, and obstruct the investigation” into the Watergate incident. Nixon’s position was untenable and he resigned, preventing any impeachment from happening.

A few decades later, there was a president impeached for obstruction of justice: Bill Clinton. Clinton at one point faced four articles of impeachment, two centered on perjury (including lying under oath when offering testimony for an affidavit) and one on obstruction related to his efforts to prevent information about his affair with Monica Lewinsky from coming to light — including encouraging her to give false testimony.

“Republicans say that, before Lewinsky became a possible witness, she and the president discussed fabricated stories to use to cover up their relationship,” The Post reported in 1999, “and that, according to Lewinsky’s testimony, the president repeated those stories when he telephoned her on Dec. 17 to say she was on the Paula Jones witness list. As Lewinsky recalled that conversation, Clinton said, ‘You know, you can always say you were coming to see Betty or that you were bringing me letters.’”

The House Judiciary Committee delivered four impeachment charges against Clinton. Two were ultimately approved by the House.

Both the Nixon and Clinton incidents have taken on new significance with the report Thursday evening from BuzzFeed News that special counsel Robert S. Mueller III had evidence — including from President Trump’s former attorney Michael Cohen — that Trump had encouraged Cohen to lie to Congress about a proposed development deal in Moscow. Cohen’s already admitted guilt in providing that false testimony, which included denials that discussions about the project had continued past January 2016 and that he hadn’t considered asking Trump to travel to Moscow to move it forward.

The response from Democrats to this report was swift. Rep. Ted Lieu (D-Calif.) called for the House Judiciary Committee to bring hearings to consider if Trump committed high crimes — one of the criteria for impeachment. Were the House to pass articles of impeachment against Trump, they would then go to the Senate, where a two-thirds majority would be required to remove Trump from office. In 1999, Clinton survived the removal vote, and he served out his term.

What’s interesting about that vote 20 years ago, though, is that there are still a number of members of Congress who were around at that point and supported punishing Clinton for obstruction of justice — including 14 Republican senators. That’s interesting in part because of another number: Assuming every Senate Democrat voted to oust Trump, they would need to be joined by 20 Republicans.

Who are those 14 senators? Well, at the time, eight were members of the House who supported the third article of impeachment against Clinton. (Two representatives who sat on the House Judiciary Committee in the prior Congress, Reps. Jim Sensenbrenner (R-Wis.) and Steve Chabot (R-Ohio), also voted to impeach Clinton.)

That includes now-Sen. Lindsey Graham (R-S.C.), who not only voted to impeach Clinton on obstruction but actually served as one of the prosecutors of the case against Clinton before the full Senate.

“If you believe he obstructed justice in a civil rights lawsuit, don’t move the bar any more,” Graham implored the senators. “We have moved the bar for this case a thousand times.”

“You don’t even have to be convicted of a crime to lose your job in this constitutional republic if this body determines that your conduct as a public official is clearly out of bounds in your role,” he said at another point. “[I]mpeachment is not about punishment. Impeachment is about cleansing the office. Impeachment is about restoring honor and integrity to the office.”

Among the then-sitting senators he and the other prosecutors swayed — 50 of the 67 needed to remove Clinton from office — were six current senators.

This list was longer two years ago. At that point a total of 17 senators had voted to impeach Clinton on obstruction of justice charges or to have him removed from office as punishment. It’s not likely that even all 14 of those who supported punishing Clinton would support punishing Trump now; you’ll have noticed that the bars in the above diagrams are pretty uniform in their coloration as a function of party solidarity. Would these 14 Republican senators hold the same position now, should BuzzFeed News’s reporting be confirmed with public evidence? Does Graham, now one of Trump’s closest allies, still worry about cleansing the Oval Office? Would 20 Republicans buck their president in a time as polarized as this one?

We may well find out.